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bf5e3a30f7
This reverts commit 8a08c5fd89.
It turns out while this is a perfectly valid and long overdue thing to do
for user initiated discards / zeroing from the ioctl handler, it actually
breaks file system use of the discard helper by interrupting in places
the file system doesn't expect, and by leaving the bio chain in a state
that the file system callers of (at least) __blkdev_issue_discard do
not expect.
Revert the change for now, we'll redo it for the next merge window
after refactoring the code to better split the file system vs ioctl
callers and cleaning up a few other loose ends.
Reported-by: Chandan Babu R <chandanbabu@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20240314021623.1908895-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
342 lines
8.8 KiB
C
342 lines
8.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Functions related to generic helpers functions
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/scatterlist.h>
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#include "blk.h"
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static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector)
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{
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unsigned int discard_granularity = bdev_discard_granularity(bdev);
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sector_t granularity_aligned_sector;
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if (bdev_is_partition(bdev))
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sector += bdev->bd_start_sect;
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granularity_aligned_sector =
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round_up(sector, discard_granularity >> SECTOR_SHIFT);
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/*
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* Make sure subsequent bios start aligned to the discard granularity if
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* it needs to be split.
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*/
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if (granularity_aligned_sector != sector)
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return granularity_aligned_sector - sector;
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/*
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* Align the bio size to the discard granularity to make splitting the bio
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* at discard granularity boundaries easier in the driver if needed.
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*/
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return round_down(UINT_MAX, discard_granularity) >> SECTOR_SHIFT;
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}
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int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
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sector_t nr_sects, gfp_t gfp_mask, struct bio **biop)
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{
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struct bio *bio = *biop;
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sector_t bs_mask;
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if (bdev_read_only(bdev))
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return -EPERM;
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if (!bdev_max_discard_sectors(bdev))
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return -EOPNOTSUPP;
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/* In case the discard granularity isn't set by buggy device driver */
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if (WARN_ON_ONCE(!bdev_discard_granularity(bdev))) {
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pr_err_ratelimited("%pg: Error: discard_granularity is 0.\n",
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bdev);
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return -EOPNOTSUPP;
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}
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bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
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if ((sector | nr_sects) & bs_mask)
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return -EINVAL;
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if (!nr_sects)
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return -EINVAL;
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while (nr_sects) {
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sector_t req_sects =
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min(nr_sects, bio_discard_limit(bdev, sector));
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bio = blk_next_bio(bio, bdev, 0, REQ_OP_DISCARD, gfp_mask);
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bio->bi_iter.bi_sector = sector;
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bio->bi_iter.bi_size = req_sects << 9;
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sector += req_sects;
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nr_sects -= req_sects;
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/*
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* We can loop for a long time in here, if someone does
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* full device discards (like mkfs). Be nice and allow
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* us to schedule out to avoid softlocking if preempt
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* is disabled.
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*/
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cond_resched();
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}
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*biop = bio;
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return 0;
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}
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EXPORT_SYMBOL(__blkdev_issue_discard);
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/**
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* blkdev_issue_discard - queue a discard
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* @bdev: blockdev to issue discard for
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* @sector: start sector
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* @nr_sects: number of sectors to discard
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* @gfp_mask: memory allocation flags (for bio_alloc)
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*
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* Description:
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* Issue a discard request for the sectors in question.
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*/
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int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
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sector_t nr_sects, gfp_t gfp_mask)
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{
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struct bio *bio = NULL;
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struct blk_plug plug;
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int ret;
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blk_start_plug(&plug);
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ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &bio);
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if (!ret && bio) {
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ret = submit_bio_wait(bio);
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if (ret == -EOPNOTSUPP)
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ret = 0;
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bio_put(bio);
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}
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blk_finish_plug(&plug);
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return ret;
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}
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EXPORT_SYMBOL(blkdev_issue_discard);
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static int __blkdev_issue_write_zeroes(struct block_device *bdev,
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sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
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struct bio **biop, unsigned flags)
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{
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struct bio *bio = *biop;
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unsigned int max_sectors;
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if (bdev_read_only(bdev))
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return -EPERM;
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/* Ensure that max_sectors doesn't overflow bi_size */
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max_sectors = bdev_write_zeroes_sectors(bdev);
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if (max_sectors == 0)
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return -EOPNOTSUPP;
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while (nr_sects) {
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unsigned int len = min_t(sector_t, nr_sects, max_sectors);
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bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
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bio->bi_iter.bi_sector = sector;
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if (flags & BLKDEV_ZERO_NOUNMAP)
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bio->bi_opf |= REQ_NOUNMAP;
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bio->bi_iter.bi_size = len << SECTOR_SHIFT;
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nr_sects -= len;
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sector += len;
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cond_resched();
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}
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*biop = bio;
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return 0;
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}
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/*
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* Convert a number of 512B sectors to a number of pages.
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* The result is limited to a number of pages that can fit into a BIO.
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* Also make sure that the result is always at least 1 (page) for the cases
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* where nr_sects is lower than the number of sectors in a page.
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*/
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static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
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{
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sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
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return min(pages, (sector_t)BIO_MAX_VECS);
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}
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static int __blkdev_issue_zero_pages(struct block_device *bdev,
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sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
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struct bio **biop)
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{
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struct bio *bio = *biop;
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int bi_size = 0;
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unsigned int sz;
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if (bdev_read_only(bdev))
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return -EPERM;
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while (nr_sects != 0) {
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bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects),
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REQ_OP_WRITE, gfp_mask);
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bio->bi_iter.bi_sector = sector;
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while (nr_sects != 0) {
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sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
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bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
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nr_sects -= bi_size >> 9;
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sector += bi_size >> 9;
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if (bi_size < sz)
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break;
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}
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cond_resched();
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}
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*biop = bio;
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return 0;
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}
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/**
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* __blkdev_issue_zeroout - generate number of zero filed write bios
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* @bdev: blockdev to issue
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* @sector: start sector
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* @nr_sects: number of sectors to write
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* @gfp_mask: memory allocation flags (for bio_alloc)
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* @biop: pointer to anchor bio
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* @flags: controls detailed behavior
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*
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* Description:
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* Zero-fill a block range, either using hardware offload or by explicitly
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* writing zeroes to the device.
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*
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* If a device is using logical block provisioning, the underlying space will
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* not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
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*
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* If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
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* -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
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*/
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int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
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sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
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unsigned flags)
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{
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int ret;
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sector_t bs_mask;
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bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
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if ((sector | nr_sects) & bs_mask)
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return -EINVAL;
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ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
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biop, flags);
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if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
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return ret;
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return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
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biop);
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}
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EXPORT_SYMBOL(__blkdev_issue_zeroout);
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/**
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* blkdev_issue_zeroout - zero-fill a block range
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* @bdev: blockdev to write
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* @sector: start sector
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* @nr_sects: number of sectors to write
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* @gfp_mask: memory allocation flags (for bio_alloc)
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* @flags: controls detailed behavior
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*
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* Description:
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* Zero-fill a block range, either using hardware offload or by explicitly
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* writing zeroes to the device. See __blkdev_issue_zeroout() for the
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* valid values for %flags.
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*/
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int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
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sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
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{
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int ret = 0;
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sector_t bs_mask;
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struct bio *bio;
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struct blk_plug plug;
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bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
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bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
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if ((sector | nr_sects) & bs_mask)
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return -EINVAL;
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retry:
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bio = NULL;
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blk_start_plug(&plug);
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if (try_write_zeroes) {
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ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
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gfp_mask, &bio, flags);
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} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
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ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
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gfp_mask, &bio);
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} else {
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/* No zeroing offload support */
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ret = -EOPNOTSUPP;
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}
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if (ret == 0 && bio) {
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ret = submit_bio_wait(bio);
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bio_put(bio);
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}
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blk_finish_plug(&plug);
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if (ret && try_write_zeroes) {
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if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
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try_write_zeroes = false;
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goto retry;
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}
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if (!bdev_write_zeroes_sectors(bdev)) {
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/*
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* Zeroing offload support was indicated, but the
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* device reported ILLEGAL REQUEST (for some devices
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* there is no non-destructive way to verify whether
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* WRITE ZEROES is actually supported).
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*/
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ret = -EOPNOTSUPP;
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}
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}
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return ret;
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}
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EXPORT_SYMBOL(blkdev_issue_zeroout);
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int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
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sector_t nr_sects, gfp_t gfp)
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{
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sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
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unsigned int max_sectors = bdev_max_secure_erase_sectors(bdev);
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struct bio *bio = NULL;
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struct blk_plug plug;
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int ret = 0;
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/* make sure that "len << SECTOR_SHIFT" doesn't overflow */
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if (max_sectors > UINT_MAX >> SECTOR_SHIFT)
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max_sectors = UINT_MAX >> SECTOR_SHIFT;
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max_sectors &= ~bs_mask;
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if (max_sectors == 0)
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return -EOPNOTSUPP;
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if ((sector | nr_sects) & bs_mask)
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return -EINVAL;
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if (bdev_read_only(bdev))
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return -EPERM;
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blk_start_plug(&plug);
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while (nr_sects) {
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unsigned int len = min_t(sector_t, nr_sects, max_sectors);
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bio = blk_next_bio(bio, bdev, 0, REQ_OP_SECURE_ERASE, gfp);
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bio->bi_iter.bi_sector = sector;
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bio->bi_iter.bi_size = len << SECTOR_SHIFT;
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sector += len;
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nr_sects -= len;
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cond_resched();
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}
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if (bio) {
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ret = submit_bio_wait(bio);
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bio_put(bio);
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}
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blk_finish_plug(&plug);
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return ret;
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}
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EXPORT_SYMBOL(blkdev_issue_secure_erase);
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